Comprehensive insights into the thermal and mechanical effects of metallic glasses via creep

摘要

Evolution of deformation and relaxation behaviors of a prototypical Cu_(46)Zr_(46)A_(l8)metallic glass was explored by extensive creep tests under both physical aging and cyclic loading.Deep insights into the microstructure-induced dynamic heterogeneity which accommodates creep deformation were successively revealed via experimental measurements and spectral analyses.An annihilation of local defects within metallic glass with increasing annealing time and cyclic numbers was observed through the reduction of amplitude in both activation energy spectra and relaxation-time spectra,which were also accompanied by an ascending value of β_(KWW).It is further found that the corresponding deformation units within the metallic glass do not disappear permanently,but are recoverable over the course of cyclic loading.The apparent suppressed relaxation process can be gradually alleviated with increasing resuming time between two consecutive cycles,behaving differently from physical aging,which indicates a notable discrepancy between thermal treatment and mechanical treatment.